Is the IMF top-heavy in all metal-poor environments? A critical test in Sextans A
Abstract
Massive star feedback plays an important role on the chemodynamical evolution of galaxies and the Universe. Exploring the physics of these stars in low-metallicity regimes is a necessary step to describe the first generation of stars. Our main purposes are to classify OB stars in Sextans A, potentially the Local Group iron-poorest galaxy (Z ∼ 0.10 Zsun), to estimate their physical parameters, and to determine the IMF in this metal-poor galaxy. The data reduction process of faint, extragalactic OB stars with GTC-OSIRIS-MOS is improved as a by-product. We have achieved the largest OB star catalog in Sextans A. These stars have high initial masses, between 20 and 50 Msun, and are quite young, with ages around 1-7 Myrs. In addition, we used bootstrap + Monte Carlo simulations to determine the IMF of Sextans A and its star forming regions. We find indications that the IMF of regions displaying H II bubbles (regions -B and -C) could be "top-heavy", similarly to other starburst star forming regions in the Local Group.
- Publication:
-
XIV.0 Scientific Meeting (virtual) of the Spanish Astronomical Society
- Pub Date:
- July 2020
- Bibcode:
- 2020sea..confE..56L